NQ = nitroguanidine

NQ = nitroguanidine 230 NS = nitrostarch 235 NSP = black powder - smokeless powder compound (german)... 

Nitroguanidine (NQ) is a nitramine compound containing one N-NOj group in its molecular structure. In contrast to cyclic nitramines such as HMX and RDX, its density is low and its heat of explosion is also comparatively low. However, the Mg of its combustion products is low because of the high mass fraction of hydrogen contained within the molecule. Incorporating NQ particles into a double-base propellant forms a composite propellant termed a triple-base propellant, as used in guns. 

Triple-base propellants are made by the addition of crystalUne nitroguanidine (NQ) to double-base propellants, similar to the way in which nitramine is added to CMDB propellants as described in the preceding section. Since NQ has a relatively high mole fraction of hydrogen within its molecular structure, the molecular mass of the combustion products becomes low even though the flame temperature is reduced. Table 4.13 shows the chemical composition, adiabatic flame temperature, and thermodynamic energy,/ as defined in Eq. (1.84), of a triple-base propellant at 10 MPa (NC 12.6% N). 

Dr Price also mentions (Ref 17, p 696) her previous work on NGu (Nitroguanidine) (designated by Price as NQ) which consisted only... 

Fia 6 Effect of A on shock sensitivity of various explosives. NQ-f is low-bulk-density nitroguanidine with hollow-needle crystals of about 5 n diam X 60-65 it long. NQ-h is the high-bulk-density material made up of solid particles of about GO-65 n diam. DATB, TNT, and Tetryl are, respectively, dia-minotrinitrobenzene, trinitrotoluene and trinitro-phenylmethylnitramine. RDX is cyclotrimethyl-enetrinitramine which contains 2.5% lubricant. Measurements were carried out with a standardized test (Ref 16) in which a 3.65-cm-diam test explosive confined in 0.55-cm-thick steel is the acceptor and polymethyl methacrylate is the gap material MGl = NCro filt ro uasiM i ... 

Some TNT-based formulations have been tailored, made and tested for sensitivity and ballistic performance. When TATB, DINGU and nitroguanidine (NQ) are incorporated in these formulations, they become IHEs. Further details of these formulations are available in the literature [176]. 

Gun propellants usually are single base (NC), double base (NC and NG), or triple base (NC, NG, and nitroguanidine (NQ)). Some of the newer, lower vulnerability gun propellants contain binders and crystalline explosives and thus are similar to PBX. 

Fig. 1.3 Molecular structures of picric acid (PA), tetryl, trinitrotoluene (TNT), Nitroguanidine (NQ), pentaerythritol tetranitrate (PETN), hexogen (RDX), octogen (HMX), hexanitrostilbene (HNS) and triaminotrinitrobenzene (TATB).

Nitroguanidine (NQ) was first prepared by Jousselin in 1887 (Fig. 1.3). However, during WWI and WWII it only found limited use, for example in formulations with AN in grenades for mortars. In more recent days NQ has been used as a component in triple-base propellants together with NC and NG. One advantage of the triple-base propellants is that unlike double-base propellants the muzzle flash is reduced. The introduction of about 50 % of NQ to a propellant composition also results in a reduction of the combustion temperature and consequently reduced erosion and increased lifetime of the gun. NQ can be prepared from dicyandiamide and ammonium nitrate via guanidinium nitrate which is dehydrated with sulfuric acid under the formation of NQ ... 

Another very promising melt-pour explosive is propyl nitroguanidine (PrNQ). The compound melts at 99 °C and has TNT like performance. The synthesis is easy and straight forward from commercially available NQ (Fig. 2.9b). 

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